The present invention relates to clamping objects and, in particular, tensioning band clamps about hoses using electrical control.
Many types of band clamps have been devised or advanced for use in clamping to objects, such as hoses, pipes, poles, cables and the like. Common band clamps can be provided to the user in pre-formed loops in which one or more generally circular wraps are already formed. Such a band clamp can be used with objects about which the one or more loops can be located and then subsequently tightened about the object to firmly hold the band clamp to the object. Common types of band clamps also include those having a free end that is initially wrapped about the object being clamped. Band clamps usually have a buckle or other locking-type element through which one or more wraps of the band arc made. The buckle can be useful in creating a lock for the band clamp after it is properly tightened about the object.
In conjunction with tightening or tensioning the band clamp after it is placed about the object, various tools have been implemented or disclosed that are intended to enhance or facilitate the tightening operation. In many instances, such tools are beneficial in cutting a tail portion of the band clamp after it has been tightened and in creating a desired lock so that unwanted release of the band clamp does not occur. Tools that perform the tightening, locking and cutting functions can be primarily manual, pneumatic or electrical in nature, In the case of pneumatic or electrical tools used for such purposes, the power generated results in these functions being accomplished with limited or reduced physical efforts required by the operator. Band tightening tools that are pneumatic or electrical are usually semiautomatic in that the operator of such a tool is required to perform some, but not all, of the tasks or functions associated with providing a band clamp about an object. Manual tasks that remain can include locating the band clamp about the object and inserting or otherwise locating the band clamp relative to the tool so that the tool can perform one or more of its tightening, locking and cutting functions. In one known pneumatic band tightening apparatus, a desired tension can be set for the band clamp about the object. After this is done, a pneumatic cylinder is activated to pull on the band until the desired band tension is reached. Pneumatic control can also be involved with cutting the band tail portion after the band clamp is tightened and which can also involve forming the lock that prevents unwanted release of the band clamp. When using electrical power with a band clamp, it is known to provide an electric motor that drives a gearing mechanism to which the band clamp is connected for use in tightening the band about the object.
Although different tools have been designed for use with band clamps, it would be advantageous to provide a tool, particularly one that relies on electrical power, that achieves greater control over the band clamping operations. Such a tool should be effective and efficient in tightening the band clamp, forming the band clamp lock and removing the severed tail portion after the band clamp is tightened. Furthermore, it would be beneficial for such a tool to be easily used by the operator in connection with positioning the object to be clamped and insertion, or otherwise joining, of the band clamp to the tool.
The present invention relates to an apparatus that electrically controls tightening a band clamp, cutting a clamp tail after the band clamp is tightened including as part of creating a lock for the band clamp and removing the clamp tail from the apparatus. Generally, the apparatus includes a banding system and a control system. The banding system essentially includes mechanical components or hardware for implementing the tightening, cutting/locking, and clamp tail removal functions associated with providing the band clamp about an object, such as a hose. The control system is essentially comprised of hardware components, but could include software, that controls these functions or operations. The control system can be characterized as including a control assembly and an input/output device. The input/output device can comprise one or more audible indicators and/or visual displays for providing desired information to the operator during use of the apparatus. In a preferred embodiment, a foot switch is included that must be activated at all times in order to continue operation of the apparatus. When the foot switch is released, the apparatus is deactivated. The input/output device can also include a keypad having a number of keys or input elements useful in providing desired inputs that are used by the control system, such as a desired or predetermined tension that is to be applied to the band clamp.
The control assembly is in electrical communication with the input/output device and includes an electric motor that is operably connected to a band tightening assembly. When a band clamp is prepared for tightening about an object and the electric motor is activated, the tightening of the band clamp about the object occurs. The control assembly also has a tension monitoring device that outputs data or other information related to the current band clamp tension. Preferably, the tension monitoring device includes a load cell assembly including a load cell that essentially translates the detected band clamp tension to an electrical signal. The electrical signal is received by signal conditioning circuitry that suitably prepares signals, such as the actual tension related signal for subsequent processing. In that regard, the control assembly includes processing/logic circuitry involved with determining whether the predetermined tension has been reached. After the predetermined tension is obtained, the control assembly causes the tightening of the band clamp to be discontinued, such as by de-activating the electric motor. The control assembly can also include a number of sensors including sensors related to detecting events associated with starting the tightening operation and associated with removal of the clamp or band tail after the cutting/locking operations. Referring to the band tightening assembly, it preferably includes a mandrel about which portions of the band clamp are wrapped as the mandrel is turned using the electric motor and a gear mechanism. The band tightening assembly also includes a gripper mechanism that firmly grips the end portions of the band clamp, which end portions are inserted into the apparatus. The gripper mechanism has an open position for receiving such band clamp portions prior to tightening the band clamp about the object. The gripper mechanism also has a closed position, which is maintained during tightening of the band clamp. In a preferred embodiment, the gear mechanism has at least one gear and the load cell of the load cell assembly is positioned parallel to that gear. The load cell can also be attached to a thrust member, which is joined to the one gear, and the load cell receives an input related to the actual tension of the band clamp using a force associated with the one gear on the thrust member.
The banding system also includes a band cutting/locking assembly that is activated or otherwise caused to operate after the band tightening operation is completed. The band cutting/locking assembly can include electrical control, such as an electric motor, that initiates a cutting device to sever the clamp tail from the tightened band clamp. The cutting device includes a cutting head that performs the cutting operation. The cutting device is preferably removable from the apparatus so that one of a number of selectable cutting devices can be removably connected to the apparatus for providing a desired or particular cutting/locking of the band clamp.
The banding system also includes a band ejection assembly involved with removal of the severed clamp tail from the apparatus. An ejector cup of the band ejection assembly is positioned about the mandrel when the band clamp is being tightened. The ejector cup is moved away from the mandrel under control of the control system in order to remove the clamp tail from the apparatus. In one embodiment, the ejector cup has a slot through which the severed clamp tail can escape once the ejector cup is moved laterally away from the mandrel.
In accordance with using the apparatus with a band clamp, appropriate inputs are input to the input/output device, such as the desired tension to be applied to the band clamp. Other inputs that could be entered include the type, width and material of the band clamp, which information can be used by the apparatus in providing the desired tension. Additionally, the object, such as a hose, and a band clamp properly positioned thereabout are suitably placed relative to the apparatus including inserting a free end of the band of the band clamp into the gripping mechanism of the band tightening assembly. With regard to proper insertion, the mandrel is at its home position, which can be determined using a visual and/or audible indicator of the input/output device. After the proper set-up is established, the apparatus is activated including applying power to the electric motor using the foot switch. Rotation of the shaft of the electric motor results in rotation of the mandrel and the gripper mechanism that is operably connected to the mandrel. During the initial rotation of the mandrel, the gripper mechanism closes to firmly grip the free end of the band clamp. As rotation of the mandrel continues and the band clamp is being tightened, a curved clamp tail is created, which is positioned about the outer surface of the mandrel within the ejector cup of the ejection assembly. As the band clamp continues to be tensioned, the control assembly continuously compares the current actual tension of the band clamp with the desired tension that was previously input. When the actual tension equals, or substantially equals, the predetermined tension, the tightening operation of the apparatus is stopped including turning off the power to the electric motor. In obtaining the current actual tension, an electrical signal output by the load cell is received by the signal conditioning circuitry and the processing/logic circuitry of the control assembly in connection with comparing this actual tension related signal with the magnitude of the desired tension.
Depending on the desired tension to be applied to the band clamp, the clamp tail can make less than one wrap, substantially one wrap or more than one wrap about the mandrel outer surface. When the clamp tail is wrapped more than once about the outer surface of the mandrel, tightening of the band clamp continues past the home position of the mandrel. In such a case, the processing/logic circuitry of the control assembly is involved with determining that the actual tension is at least equal to an override tension indicative of the fact that the band tightening operation should continue since the desired tension has not yet been reached. In another situation as well, the electric motor is not powered off when the mandrel is at the home position. In this situation, the home position is detected after the tightening operation is complete and the clamp tail has been severed. The electric motor must be activated for a short period of time to enable the clamp tail to be properly ejected. However, the mandrel may reach the home position during this short period of activation. A timer is employed in determining that the electric motor has not been powered on for a predetermined interval of time. Until that predetermined interval of time is reached, power continues to be applied to the motor past the home position so that the clamp tail can be properly ejected.
After the band clamp has been tightened, the next steps involving the apparatus include using the band cutting/locking assembly to sever the clamp tail and to form the desired lock using the cutting device having the selected or predetermined cutting head. In that regard, the motor of the band cutting/locking assembly is activated to cause an actuator assembly to move the cutting device in a manner that causes the cutting head to sever the clamp tail. With regard to one embodiment of a particular type of band clamp, the clamp tail to be severed is released a short distance by reversing the direction of the shaft of the electric motor. The operator then moves this particular band clamp to a desired position and subsequently the cutting device is caused to move in order to sever the clamp tail. Generally, a number of the same kind of band clamps are to be joined with an associated one of a number of objects. A removable cutting device is selected for this number of particular band clamps. When another set of different band clamps are employed requiring a different cutting device, the currently used cutting device can be replaced with the different cutting device.
At the completion of the operation involving the cutting of the clamp tail and forming the lock on the band clamp, the apparatus next proceeds to implement the steps that eject or otherwise remove the severed clamp tail from the apparatus. During the band tightening steps, the ejector cup of the band ejection assembly is located over the mandrel. After the clamp tail is severed, the ejector cup is moved laterally away from the mandrel using an ejection solenoid that is activated by the processing/logic circuitry of the control assembly. After the ejector cup has moved laterally a sufficient distance, the severed clamp tail is able to exit or escape through the slot in the ejector cup. With the removal of the severed clamp tail, the ejector cup can be re-positioned over the mandrel by movement thereof in the opposite lateral direction.
With the completion of the tightening, cutting, locking and clamp tail removal operations, the next band clamp can be provided for clamping about another object. The necessary parameters, such as the desired tension to be applied, may be the same so that the previous inputs are used again. It may be necessary to locate the mandrel at its home position so that the gripper mechanism is open to receive the free end of the next band clamp, which is located about the next object to be clamped. After doing so, the foot switch can be activated and the same operations previously described can be accomplished.
Based on the foregoing summary, a number of salient features of the present invention are noted. Substantial electrical controls are provided for tightening, cutting, locking and clamp tail removal in connection with the operations for properly joining a band clamp to an object. Such greater electrical control includes the capabilities of providing various inputs and obtaining information by means of different visual and audio outputs. In conducting the tensioning of the band clamp, a strong grip of the band occurs using an openable gripper mechanism having a non-linear gripping surface contacted by the band portions. This design insures that no slipping of the band occurs during the tensioning thereof. A load cell is utilized for use in indicating the current actual tension being applied to the band clamp. The load cell is arranged with one or more gears of a gear mechanism to eliminate, or at least reduce, the effects of the gear mechanism on the measured actual tension. In that regard, wear, degree of lubrication, and other factors that might affect operation of the gear mechanism do not negatively impact the measured actual tension. The cutting device of the band cutting/locking assembly is removable. Consequently, different, selected cutting heads can be employed to provide various types of cutting/locking features. The band tightening assembly can include a mandrel about which the clamp tail is wrapped or otherwise positioned so that a curved tail portion results, instead of a relatively straight tail portion, thereby reducing the space that is occupied by the clamp tail to be severed. Additionally, the band ejection assembly effectively removes the severed clamp tail from the apparatus by an efficient lateral movement of an ejector cup that allows the severed clamp tail to escape from a slot in the ejector cup.
Additional advantages of the present invention will become readily apparent from the following discussion, particularly when taken together with the accompanying drawings.